function format_block( startNode, element_name, preserve ) {
    var nodeContent = startNode.innerHTML;

    // Because people will moan like hell if these are left in
    nodeContent = nodeContent.replace( /xmlns=\"http:\/\/www\.w3\.org\/1999\/xhtml\"/g, "" );

    // Create a new tag with the desired name.
    var newBlock = document.createElement( element_name, "http://www.w3.org/1999/xhtml" );

	if (preserve) {
		// Copy over all the attributes from the old block-level tag.
		var arrAttr = startNode.attributes;
		for(var j = 0; j < arrAttr.length; j++) {
			if(arrAttr[j].value != "" && arrAttr[j].value != "null") {
				var a = arrAttr[j].nodeName.toLowerCase();
				var v = arrAttr[j].nodeValue;
				
				switch(a) {
					case "class":
						newBlock.className = v;
						break;
					case "style":
						newBlock.style.cssText = v;
						break;
					default:
						newBlock.setAttribute( a, v );
						break;
				}
			}
		}
	}
    
    // Inject the content from the old tag and replace the node.
    newBlock.innerHTML = nodeContent;
    
    return newBlock;
};
